Stoker



Dec. 2, 1924.

I l 518 024 M. URQUHART 9 STOKE'R Filed N. 22, 1922 2 SheetsSheet 1 I1 7 WITNESSES INVENTOR W 2 fg A TTOR/VEYS Dec. W24. 1,518,024

M. B. URQUHART STOKER 7 Filed Nov. 22, 1922 2 Sheets-Sheet 2 m M 0 n A QQN v \\\\\\N\\\\\\\\\ Mrinnocr-r B. URQUHAR-T, or DENVER, COLORADO.

STOKER.

Application filed November 22, 1922. Serial No. 602,570.

To all whom it may concern:

Be it known that I, MURDOOH B. URQU- HART, a citizen of the United States, and a resident of Denver, in the county of Denver and State of Colorado, have invented certain new and useful Improvements in Stokers, of which the following is a specification.

. This invention relates to a combined grate and stoker and has for its object the provision of a device for automatically maintaining the grate clean and for progressively advancing the fuel from the front to the rear of the furnace with grate bars so arranged and constructed that they will not permit sifting of the lowest grades of coal, lignite or screenings through said grate.

A further object of the invention is to provide a plurality of grate bars having air passages therethrough and located in a direction which is at an angle to the direction of movement of the fuel in the furnace whereby the air passages will not be clogged by ashes and will not permit the escape of the hot coals through the grate bar.

A further object of the invention is the provision of a combined grate and stoker having its grate bars so arranged as to not only prevent the formation of clinkers and loss of hot coals through the grate bars but to eliminate smoke by the combustion in the furnace of the volatile substances of the coal that usually and primarily distil off and escape through the fines since the coal is progressively advanced not only down ward'ly in a vertical manner but longitudinally of the furnace whereby the later charges of coal are properly heated before being advanced to the hotter portions of the fire box for consumption.

The. invention is illustrated by way of example in the accompanying drawings, in which Figure 1 is a view in perspective of the combined stoker and grate.

Figure 2 is a longitudinal section taken along the line 22 of Figure 5, with alternate grate'bars in section showing horizontal air passages.

Figure 3 is a fragmentary view showing in detail the pivotal connection for the dump grates.

Figure 4; is a side view of one of longitudinal side members comprising supporting frame.

the the.

Figure 5 is a front view of a grate bar and its related parts.

Referring to the drawings, the combined stoker and grate comprises a rectangular frame inclined at an angle to the horizontal and provided with longitudinal side memhers I and 2, with a transverse horizontal member or dead plate a and a transverse horizontal connecting member 5 located at a lower plane than the horizontal transverse member 4c. The longitudinal side members are provided at their rear ends With a portion 6 formed at an angle to said members but less inclined to the horizontal than said members. The portion between the grates and the horizontal connecting member 5 provides a space for mounting the dump grates which will presently be described.

On the'inner opposite faces of a pair of the longitudinal side members 1 and 2 are formed spaced parallel tracks 7 with certain tracks arranged in the same horizontal plane. Four of these tracks in two sections of the grate therefore Will be in the same horizontal plane with the next succeeding groups of four tracks arranged in horizontal planes at different elevations from the lowermost group of tracks.

Since both sections of the grate as shown in Figure 1 are similar in construction, a description of one will suffice for a description of the other. The sections of the grate, as shown, set up are adapted to be located in alinement with the number of sections always being determined by thewidth of the furnace in. which the grates are employed. A pair of the tracks included on the opposite faces of the longitudinal side members 1 and 2 are adapted to receive a grate bar 9, while a pair of the tracks which are disposed at a higher level than the first mentioned tracks are adapted to receive a grate bar 9 so that the one section of the grate will be composed entirely of alternate grate bars 9 and 9'. The grate bars 9 are adapted to be reciprocated or in other words moved outwardly from a grate section While the grate bars 9 remain stationary. WVhen the bars 9 are reciprocated the bars 9 remain stationary. As will be presently described, a separate operating means is employed for reciprocating the two series of grate bars independently of each other.

Each grate bar is provided with a top 11, side members 12, laterally projecting ribs 13 adapted to rest on the tracks 7,-and

an inclined front face 3 which is provided with a plurality of horizontal openings 14. The mouth of the openings leading toward the furnace is of less width than the mouth of the openings which are directed to the ash pit 15. These openings provide air passages for admitting a sufficient quantity of air to the furnace to maintain the proper cmbus tion of the fuel. Tracks '7 operate in grooves 8 formed in the side members 12 of the grate bars 9 and 9.

The front end of the frame is supported through the horizontal dead plate 4 by the front wall 16 of the furnace, while the rear end is supported through the transverse horizontal member which is mounted on a metal plate 17 supported in position on the rear wall 18 of the furnace. In the longitudinal side members 1 and 2 are formed alined openings which are located in staggered relation and adapted to form bearings for the hollow rock shafts 19 and 20. Each alternate shaft, which is desig nated by the numeral 19, is equipped with rocker arms 21 and 21 disposed at opposite ends of the shaft. The rocker arm 21 is rigidly secured intermediate its ends to the shaft, while the rocker arm 21 is rigidly secured at its lower end. The upper ends of the rocker arms are provided with teeth 23 adapted to engage teeth 24 projecting from the lower edge of the side members 12 of the grate bars 9.

The rock shafts are similarly equipped with rocker arms 25 and 25 and provided with teeth adapted to engage teeth depending from the lower edges of the side members 12 of the grates 9. The rocker arms 21 are pivotally connected at their lower ends to a pair of bars 22 whereby the rocker arms 21 are connected for simultaneous movement through said connecting member 22. A link 28 is pivotally connected to a pin 27 which is mounted in the bars 22 and has its outer end slidalole through an opening in the front wall 16 of the furnace. An operating lever 29 pi\' otally mounted at 30 is connected with the link 28 for recipro eating the link and likewise reciprocating the bars 22. lteciprocation of the bars 22 causes oscillation of the arms 21 and 21 thereby reciprocating the bars 9.

The rocker arms 25 and 25 are oscillated in a similar manner to reciprocate the grate bars 9 All the lower ends of the rocker arms 25 are pivotally connected for simultaneous movement by a pair of strap irons 26. The arms 21 which reciprocate the grate bars 9, are located upon one side of the grate while the rocker arms 25 are located at the opposite side of said grate. It will be seen that the separate bars of reciprocating strap irons 22 and 26 are likewise located upon opposite sides of the grate. The star-p irons 26 are connected to a link 28 which is similar in construction to the link 28, with a separate operating lever 29 for causing simultaneous movement of all the rocker arms 25 and reciprocation of the grate bars 9. The arms 25 are broken away to show the rocker arm 25 in Figure 2.

The grate bars 9 and the rocker arms 25 and 25 are provided with cooperating teeth in a manner similar to the construction that has been described for the rocker arms 21 and the grate bars 9. Between the portion 6 of the longitudinal side members 1 and 2 is formed an opening which is closed by a dump grate 31. The dump grate comprises a plate having tapered perforations 33 forming openings between the furnace and the ash pit 15. Integrally formed with the dump grate 31 is a depending member 34 which is pivotally connected at its lower end to a reciprocating rod v=56 provided with a hand grip 37 extending beyond and outwardly of the front wall 16 of the furnace. The reciprocating rod 36 has a hearing at 38 in an opening in the wall 16. A keeper on the wall 16 ofthe furnace is adapted to be engaged by a member 40 formed on the reciprocating rod 36 to maintain the rod in a predetermined position for holding the dump grate in its closed position.

The inner adjacent faces of the longitudinal side members of the frame are provided with oppositely disposed lugs 39 which are adapted to receive the semi-circular bosses 41 providing journals for pivotally supporting the dump grate 31.

Goal is admitted through a hopper adj acent the front portion of the furnace and over the dead plate 4 which is the highest point of the grate so that the fuel will be required to move along the inclined surface of the plurality of grate bars before it reaches the dump grate 31. When it is desired. to advance the coal along the grate surface it will be only necessary to rock the levers 29 and 29 which will cause the alternate grate bars 9 and 9 to be reciprocat-ed forwardly and reaiwvardly and progressively for advancing the coal towards the dump grates thereby eliminating the necessity of using any auxiliary device for the purpose. Furthermore by supplying coal through a hopper or in any approved manner to the top of the grate no fuel doors are required to be opened so that no cold air is admitted to the furnace. Furthermore the raking of the furnace by the mechanical stoker will likewise eliminate doors that usually admit quantities of cold air to the furnace. The oscillation of the levers 29 and 29 and the horizontal sliding movement of alternate grate bars will al ways provide an active and uniform fuel bed and prevent the formation of large clinkers, since clinkers will not be permitted by the reciprocating and shearing action of the grate bars, to adhere or grow in proportion during their travel toward the dump.

\Vhen desired the rod 86 may be actuated to damp ashes accumulated on the dump grates into the pit 15.

As shown in Figure 2, each end of an alternate grate bar is offset from the next lower bar and when the alternate grate bars are reciprocated back and forth, any ashes or clinkers that would tend to reston the offset end of the grate bars will be sheared off and forced downwardly towards the dump grates when the levers 29 and 29 are reciprocated.

Natural or forced draught may be employed in the operation of the furnace. The grate bars may be manually or mechanically operated.

lVhat I claim is:

l. A combined stoker and grate comprising a frame, inclined at an angle to the horizontal, a series of horizontal grate bars arranged in the frame, grooves formed on opposite ends of the grate bars, horizontal tracks on the inner faces of the side members of the frame engaging the grooves in the adjacent ends of the grate bars, the front. faces of the grate bars being inclined at an angle to the vertical and provided with vertical series of horizontal openings, and means connected with alternate grate bars of the frame for reciprocating the bars in a horizontal plane.

2. A combined stoker and grate comprising a frame inclined at an angle to the horizontal, a series of grate bars in the frame, horizontal grooves formed on opposite ends of the grate bars, horizontal tracks on the inner faces of the side members of the frame engaging the grooves in the adjacent ends of the grate bars, the front faces of the grate bars being inclined at an angle to the vertical and provided with horizontal openings, alternate grate bars being connected for simultaneous reciprocating movement and forming two sets of grate bars movable independently of each other, rockable means for each set of grate bars, and means for oscillating the rockable means of each set whereby one set may be reciprocated in staggered ,relation with the other set.

3. A combined stoker and grate comprising a frame inclined at an angle to the horizontal, a series of grate bars mounted in. the frame, said bars being provided with horizontal grooves on their opposite ends, horizontal tracks on the inner faces of the side members of the frame engaging the grooves in the adjacent ends of the grate bars, the front faces of the grate bars being inclined at an angle to the vertical and provided with horizontal openings, rookable means connected with the grate bars with alternate rockable means connected for simultaneous movement, means for each of the alternate rockable means for reciprocating sets of the alternate grate bars, the alternate bars of one set being movable in staggered relation with the alternate bars in the other set, and dump grates pivotally mounted on the frame adjacent the lowermost grate bars for receiving and transferring ashes from the grate bars.

4. A combined stoker and grate, comprising a substantially rectangular frame provided with longitudinal side members inclined at an angle to the horizontal, spaced parallel tracks on opposite inner faces of the longitudinal side members, grate bars having horizontal grooves formed in their opposite ends engaging the tracks, said grate bars having their front faces inclined at an angle to the vertical with certain of the bars having their lower edges offset with alternate bars and progressively arranged in different horizontal planes with the alternate bars, sets of teeth depending from the bottom of the grate bars, rock shafts mounted at their oppositeends in the longitudinal side members, rock arms rigidly connected intermediate their ends to the rock shafts, other rock arms connected at their lower ends to the shafts, bars pivotally connected alternately with the lower ends of the first mentioned rock arms, teeth on the upper end of the rock arms adapted to engage the teeth depending from the grate bars, )ivotally mounted levers, a. link connecting a lever with one of the last mentioned bars for oscillating said bar and like-' wise rocking the alternate arms whereby alternate grate bars are reciprocated horizontally, the front faces of the grate bars being provided with horizontal openings whereby air is admitted to the furnace without the loss of fuel when said bars are agitated.

MURDOC'H B. URQUHART. 

